Investigating the Potential of Using High Performance Concrete in Precast High Speed Rail Bridges

Abstract

High Speed Railway (HSR) bridges are limited in design by the sudden, heavy, repetitive nature of the vehicle loading. As a result, prestressed concrete HSR bridges are stockier than highway bridges to ensure high mass, stiffness and resistance. Different types of prestressed concrete bridges have been implemented, with a number being constructed using prefabrication techniques. However, the concrete currently used for HSR bridges uses conventional strength levels. Considering the technological improvements that have led to much stronger concretes being available, implementing these into HSR bridges could bring significant benefits.

Experience of the use of High Performance Concrete (HPC) in HSR is limited, and the use of Ultra High Performance Concrete (UHPC) is restricted to the construction of only a small number of highway and pedestrian bridges. Combining HPC and UHPC with prefabrication, utilising the multiple benefits of precasting identified in literature, could optimise HSR bridge solutions. However, investigations are needed to determine the impact of reducing the bridge mass on the dynamic behaviour, potentially causing unsafe and/or uncomfortable, increased acceleration levels in the bridge, which would not satisfy the serviceability limit state of vibrations.

By performing parametric analysis on a finite element model of a HSR bridge, potential geometrical and material strength changes are investigated to identify their effect on acceleration levels of the bridge. From this the promising regions where implementation of HPC and UHPC would be beneficial can be identified.